Thanks for reporting this! It's something we've seen in the past... this is likely due to the ratings of deleted users somehow not being cleaned up with them. I'm hoping this is due to an interrupted process, and not the actual reappearance of the bug.

As "imdb" is not a deleted user itself, I guess this accounts ratings show up in lieu of deleted user accounts?

Question: Don't these errors propagate throughout the whole system (affecting TCIs and PSIs)? I mean such an error affects other numbers, which in turn affect other numbers. Once you have caught the bug, how long does it take for the system to "heal", i.e. for the secondary distortions (down the road) to disappear ?